Sheet-holding means for cylinders of printing presses and the like



July 19, 1938. J. F. .mousEK SHEEi HOLDING MEANS FOR CYLINDERS OFPRINTING PRESSES AND THE LIKE Filed May 1, 1935' l Q b f a 5 43/ATTORNEY INVENT OR.

Patented July 19, 1938 UNITED; STATES PATENT, orrlcr.

SHEET-ROWING lVIEAN S FOR CYLINDERS OF PRINTING PRESSES AND THE LIKEJoseph F. Jirousek, Cleveland, Ohio, assignor to The Chandler & PriceCompany, Cleveland,

Ohio, a corporation of Ohio Application May 1, 1935, Serial No. 19,206

- 7 Claims. (01. 101-4151) accuracy of alignment after the sheet isclamped.

A still further object is the provision of quickacting release forremoval of the clamped sheet. Other objects and advantages will appearas the description proceeds.

To the accomplishment of the foregoing and related ends, the invention,then, comprises the features hereinafter fullydescribed, and articularly pointed out inpthe claims, the following description and theannexed drawing setting forth in detail certain illustrative embodimentsof the invention, these being indicative however, of but a few of thevarious ways in which the principle of the invention may be employed.

In said annexeddrawing:

Fig. 1 is a plan view of a cylinder embodying the invention; Fig. 2 is atransverse section thereof, on enlarged scale, takenon a planesubstantially indicated by line 11-11, Fig. 1; Fig. 3 is a fragmentarysimilar view showing the parts in releasing position; Figs. 4 and 5 areside elevational and front elevational views respectively of a detail ofthe clamping mechanism; and Figs. 6 and '1 are detail sectional viewstaken substantially on lines VIVI and VII'-VII, respectively, Fig'. 1.

The cylinder body C may be of any usual or preferred construction, andmay involve for instance a shell 2 having a ledge 3 upon which arecarried means for holding one end of a. sheet P, such for instance as azinc lithographic plate, such means comprising a fixed jaw Q, and acooperating adjustable jaw 5, the latter being tightened into holdingposition againstgthe end of the sheet 6 by tightening means, such asscrews 7. Desirably, the

latter have recessed heads or an internal wrenchhold 8, thereby offeringlittle obstruction externally. With the sheet fastened by the series ofend-holding jaws 5, the body of the sheet is drawn around the cylinderto engage in theduced portions to serve as journalaland these riderespectively in a fork H in the form of a slide having a small excursionof movement on' the plane of the base of the jaw. .The slide it has'astem extension l5 which rides through a slide mounting opening'in'thebaseljaw, and a compression spring l6 surrounding" the stem and locatedbetween the slide and the jaw'abutments serves to normally urge theslide into its for- ,ward position. Rearwardly, of the jaw member ID isa latch l'l pivoted to the jaw member at It, and having an openingthrough which the stem l5 extends, the opening being such-that the stempasses freely through the latch but when desired the stem may be pulledback by the latch to release the jaw member l2, by reasonof the latchcoming against an abutment-pin IS on the stem for such release movement;The inclined plane upon which the roller, l2 moves is convenientlyprovided by end members if! secured to the base jaw It by suitablescrews s. With such arrangement, .the jaw-roller l2 with its slide itmay have a range of movement within the space between the jaw member iiiand the jaw member II, and as the roller moves for:- wardly it travelsup the inclined plane surfaces l3, I3 and thereby binds more tightlyagainst the plate to grip the same against the jaw ll.

The latter may be knurled or roughened on its set on a rock-shaft 20,and by provision of a spring 2! between the shell 2, in a suitable abutment recess 22 for instance while the other end of the spring seatsagainst an abutment plate 23 carried by the shank of the jaw Ill, auniform rearward thrust on the jaws i0 is had, thus tending to maintainsuitable tension and tightening action upon the sheet being held. Ascrew head 24 may convenient-1y serve as centering and re taining meansfor the spring with respect to the abutment plate 23. The jaw body l0, 1I, may be swung forward on shaft 20 against the action of the spring ifa hand tool be inserted in a convenient hole 9 for this purpose, thusaifording a handle and leverage. I

By providing the jaw member 4 in the form of a bar in common for theentire set of endclamps, a nicety of adjustment after the sheet isgripped, may be had. It sometimes occurs that even when properlyinitially gauged, a sheet or lithographic plate is ultimately found tobe .bar, abutting'against a suitable surface on the cylinder thus servesto advance or retard one end of the bar as compared with the other, asmay be necessary in any given instance to skew the sheet or platesumciently to effect the desired alignment. The jaws l, 5, are providedwith gauge pins 21, these being fixed in the jaw-bar and projecting intoopenings 28 in the jaw 5. By provision of a lip-lug 29 on the jaw 5,engagement of the latter relative to the jaw l is assured in uniformmanner, so'that the gauge pins 21 will always properly enter theopenings 28 in the cooperating jaw and notinterfere. is normally urgedinto open position by a spring 30 between the jaws, centered about aretaining pin 3i and seating at each end in appropriate recesses in thejaw surfaces.

The manner of use of the device will be under stood from the foregoing.A sheet to be held in position, for instance a zinc lithographic plateis brought into position with one end in the jaws I, 5, these beinginitially in open position, the screws 1 being released for that purposeso that the springs 3D maintain them open. With the end of the platepushed into position against the row of gauge pins 21., the movable jawsare set down into clamping position by wrench-tightening .each of thescrews 1, and thereby this end of the plate is gripped. The plate isthen wrapped around the cylinder and, as the operator swings the jaws llforwardly by a hand wrench or tool inserted into one of the holes 9, thefarther end of the plate is thrust into the jaws II, and rides over thejaw-rollers l2, these being displaced backwardly on the give of thesprings l3, sufficiently to allow such admission, but immediately oncessation of the thrusting movement of the plate, the jaw-rollers I!hold the plate. When it is desired to remove the sheet P, the latches I!are drawn back from the jaws ll thereby pulling the stems l5 and jawrollers l2. into release and the sheet may be drawn out of the jaws.Undue movement of the jaw units III is guarded against in anypositioning by suitable stops. Thus, a stop-projection 33 carried by thejaw at the rear, by engaging against the shoulder 34 on the cylinderprevents the jaw being swung too far back. A stop projection 35 at thefront of the jaw serves to abut against the cylinder and prevent the jawitself from contacting closely.-

Other modes of applying the principle of the invention may be employed,change being'made as regards the details described, provided thefeaturesset forthin any of the following claims, or ,the equivalent of such, beemployed.

. I therefore particularly point out and distinctly claim as myinvention:

1. In mechanism of the character described, a cylinder and means forholding sheet material about its periphery, including a plurality ofjawcouples for holding one end of the sheet to the cylinder, saidcouples having each an interposed spring and a gauge pin, a bar incommon-mounting said jaw-couples, a central pivot for said bar, aregulating screw at each end of said bar, and self-tightening clampmeans for the other end of the sheet, said means having a roller-jawelement and a jaw element for receiving the same,

The. jaw 5.

and an inclined surface upon which said roller element may travel.

2. In mechanism of the character described, a cylinder and means forholding sheet material about its periphery, including a plurality ofjawcoupies for holding one end of the sheet to the cylinder, saidcouples having each an interposed spring and a gauge pin, a bar incommon mounting said jaw-couples, a central pivot for said bar,

a regulating screw at each endof said bar, and self-tightening clampmeans for the other end of the sheet, said means having a roller-jawelement and a jaw element for receiving the same, an inclined surfaceupon which said roller element may travel, a slide for mounting saidroller-jaw element, a stem extending rearwardly from said slide throughsaid other jaw element, and a spring interposed between said slide andsaid other jaw element.

3. In mechanism of the character described, a cylinder and means forholding sheet'material about its periphery, including a plurality ofjaw- .couplesfor holding one 'end of the sheet to the cylinder, saidcouples having each an interposed spring and a gauge pin,'a bar incommon mounting said jaw-couples, a central pivot for said bar, aregulating screw at each end of said bar, and self-tightening clampmeans for the other end of the sheet, said means having a roller-jawelement and ajaw element for receiving the same, an inclined surfaceuponwhich said roller element may travel, a slide for mounting saidroller-jaw element, a ,stem extending rearwardly from said slide throughsaid other jaw element, a spring interposed between said slide and saidother jaw element, and a releasing latch for engaging said stem.

4. In mechanism of the character described, a cylindur and means for:holding sheet material about its periphery, including a plurality oijawcouples for holding. one end of the sheet, each couple having aninterposed spring and a gauge pin,- a bar for mounting said couples incommon, a pivot centrally of said bar, an adjustablescrew at each end ofsaid bar, and self-tightening clamp means for the other end-of thesheet. said means having a plurality of roller-jaw elements, cooperatingjaw elements receiving the same,

a rock-shaft upon which said cooperating jaw elements are carried, aspring normally swinging said cooperating jaw elements rearwardly, andan inclined plane surface upon which each roller-jaw element may travel.

5. In mechanism of the character described, a i

cylinder and means for holding sheet material about its periphery,including a plurality of jawcouples for holding one end of the sheet,each couple having an interposed spring and a gauge pin, a bar formounting said couples in common, a pivot centrally of said bar, anadjustable screw at each end of said bar, and self-tightening clampmeans for the other end of the sheet, said means having a plurality ofroller-jaw elements, cooperating jaw elements receiving the same, a

rock-shaft upon which said cooperating jaw elemeans extending throughsaid jaw member for mounting the same pivotally to swing in the plane ofthe end of the sheet to be gripped, a plurality of jaw elements mountedon said jaw member and cooperating with the latter to grip the sheetmaterial, and adjusting screw means for regulating the amount ofswing-position of said jaw member relative to the cylinder.

'7. In mechanism of the character described, a.

0 cylinder and means for holding sheet material about its peripheryincluding a jaw member en-

